The present invention relates to an electrical signal delay circuit integrated in a monolithic IC and more particularly, to a circuit which outputs delay time.
In a conventional voltage detector circuit with delay function, a voltage detector circuit shown in the circuit block diagram of FIG. 9 is known. Namely a comparator 902 compares a voltage supplied from a center tap of a resistor group connected between a positive power source V.sub.DD and a negative power source V.sub.SS, and standard voltage 901. An output of the comparator 902 is delayed by an RC time constant circuit comprising a resistor 903 and a capacitor 904.
However, the conventional voltage detector circuit with delay function has the following problem if it is integrated in a monolithic IC. Namely a resistor of several hundred megohm and a capacitor of several microfarad are needed for the delay of several hundred millisecond. It is impossible to form this large resistance and capacitance on a monolithic IC since no other resistor of several megohm and capacitor of several pico farad, even if these are maximum, can be commonly formed on the monolithic IC.
Although the resistor of several megohm and condenser of several pico farad are formed on the monolithic IC for the delay of several milliseconds, a voltage detector circuit integrated in a monolithic IC is not realized practically because of a large change of delay time by a temperature change of resistance value.
An object of the present invention is to provide an electric signal delay line circuit and a voltage detector circuit with delay function which is practical, has a good transfer characteristic and can be integrated in a monolithic IC for overcoming the conventional problem.